Some people who wear contacts find their eyes become red, itchy and watery during use, and this may indicate an allergic reaction to contact lenses. One of the most common reasons for this issue is that common irritants, including pollen and dander, can build up under a lens, which means the allergens rub against the eye constantly. Some people also are allergic to the contact lens solution or the material of the lens itself. In addition, the buildup of protein on contacts can cause giant papillary conjunctivitis (GPC), in which bumps appear on the conjunctiva because the surface is so irritated, leading to allergy-like symptoms.
Contact lenses tend to collect various irritants each day they are used, especially when the people wearing them do not properly wash their hands before putting them in their eyes. For example, many people have allergic reactions to pet dander and pollen, and mold and dust also tend to cause bad reactions. Those who notice an allergic reaction to contact lenses despite keeping their hands clean and properly washing their lenses each day may find it beneficial to wear daily disposables. These are usually meant to last one day, after which they should be thrown away so fresh lenses free of the buildup of irritants can be used the next day.
It is possible to develop an allergic reaction to contact lenses stemming from certain products used during wear. For example, some people's eyes are bothered by materials in the lens itself. If this is the suspected issue, one should likely look for a different type of lens or stop wearing contacts. Similarly, some people are allergic to the contact lens solution that they use to clean and store their lenses. Switching to contact solution for sensitive eyes may help to alleviate this problem.
One major cause of an allergic reaction to contact lenses is the gradual buildup of protein on the lenses, which is called giant papillary conjunctivitis. This often allows the protein to irritate the eyes enough to cause bumps on the conjunctiva, a mucous membrane that covers the white part of the eye. Some of the most common signs of an allergic reaction to contact lenses resulting from this include redness, itchiness and discharge from the eyes. People who do not wash their lenses thoroughly, sleep in them, or wear their contacts longer than recommended tend to be most at-risk for GPC, because all those actions allow the protein to build up.